Vashishth A, et al. - The purpose of experts was to assess the incidence, demographics, surgical, and radiological correlates of incomplete and false tract electrode array insertions during cochlear implantation (CI). They evaluated the outcomes in subjects with incomplete electrode insertion (IEI). Using straight electrodes, IEI during cochlear implantation could occur with or without cochlear luminal obstruction. In this patient subset, age was noted to play an essential role in the auditory rehabilitation.

Methods

• Researchers performed a retrospective analysis at otology and skull base center.
• They assessed the charts of 18 patients (19 ears) who underwent CI with incomplete or false tract insertions of the electrode array, with at least 1 year follow-up (from 470 cases).
• The evaluation of demographic findings, etiologies, pre-operative radiologic findings, operative records, post-operative plain radiographic assessment for extent of electrode insertion, and switch-on mapping was carried out.
• Using maximum and last recorded vowel, word, sentence, and comprehension scores for subjects having IEI, audiological outcomes were assessed.

Results

• Findings suggested 4.25% to be the incidence of insertional abnormalities with 17 instances of incomplete and 2 cases of insertion into superior semicircular canal.
• The mean age and duration of deafness was noted to be 55.18 ± 4.62 and 22.12 ± 5.71 years, respectinely.
• In the IEI group, the etiologies were idiopathic, otosclerosis, meningitis, chronic otitis media (COM), temporal bone fractures, and Neurofibromatosis-2.
• Cochlear luminal obstruction was found in 29.4% cases.
• Data suggested the mean radiological and active electrophysiological length of insertion to be 20.49 ± 0.66 and 19.49 ± 0.88 mm, respectively.
• Findings did not reveal any prominent association between audiological outcomes and insertional length except in time to achieve maximum word scores (p = 0.04).
• As per the results, age at implantation displayed notable correlations with last recorded word and comprehension scores at mean follow-up of 42.9 months, and with time to achieve maximum auditory scores.